• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.9
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• pp.1648-1657
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• 1994

This paper is concerned with the development of a packet communication protocol KAX. 25 to be used on the KITSAT microsatellite. As a part of the KAX, 25 protocol, an interrupt driven I/O driver, I/O handler and an AX. 25 radio communication protocol are implemented in the KASCOM that will be used as On-Board Computer in the next missions. The implemented protocol is applied to the enginnering model of the KITSAT-2 satellite in the test configuration simulating the link between the satellite and the ground station and the compatibility of the data link layer protocol is tested.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.93-93
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• 2000

In this study, physical and data link layer protocols of FOUNDATION Fieldbus are implemented. INTEL386EX and 80196KC are used fer the CPU of PC interface board and sensor interface module, respectively The physical layer protocol of FOUNDATION Fieldbus is developed by using FB3050 chip, the fieldbus communication controller ASIC. The data Link layer protocol of FOUNDATION Fieldbus is implemented by software.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.1063-1068
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• 2008

BACnet(Building Automation and Control Networks) is a standard data communication protocol specifically designed for building automation and control systems, BACnet provides six options for data link layer protocols and these six data link layer options can be applied with various wired transmission media. Recently wireless technology prevails in automation area. ZigBee is an IEEE 802.15.4 based standard communication protocol for low-rate wireless personal area networks. In this study, we propose a BACnet over ZigBee model that adopts ZigBee communication channel as a wireless data link layer protocol in a BACnet-based communication network system. The technology proposed in this paper can expand the BACnet application using the advantages of wired and wireless integrated network solution.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.235-236
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• 2006

IEEE 802.16 networks support mobile stations (MSs) to access broadband wireless networks while moving at a vehicular speed. However, IEEE 802.16 networks do not provide link layer native multicast capability because of point-to-multipoint connection characteristic. Due to this feature, it is not easy to adopt protocols or applications which need native link layer multicast capability. In order to solve the multicast support problem, we use the built-in LAN emulation feature of IEEE 802.16 which is based on Convergence Sublayer (CS). Our proposed operational procedures support not only the delivery of link local scope multicast packets, but also the delivery of non-link local scope multicast packets such as site local or global scope multicast packets. We also present the method of forming multicast Connection Identifier (CID) which is used to transport IP packets over IEEE 802.16 networks.

• Journal of Korea Multimedia Society
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• v.15 no.12
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• pp.1464-1474
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• 2012

In this paper, we propose a QoS (Quality of Service)-aware and cooperative resource reservation scheme using cross-layer link adaptation for wireless high definition video transmission through UWB (Ultra Wide Band) network with D-MAC (Distributed Medium Access Control). A wireless high definition video transmission system usually requires stable high throughput even without line-of-sight, e.g., a destination device in another room separated by a wall. Since the WiMedia D-MAC supporting DRP (Distributed Reservation Protocol) scheme causes lots of DRP resource reservation conflicts due to failure of beacon detection in wireless channel environment, overall performances of the WiMedia D-MAC can be deteriorated. And the current WiMedia MAC standard has not considered QoS provisioning even though QoS parameters such as a range of service rates are provided to each traffic stream. Therefore, we propose Relay DRP protocol with QoS-based relay node selection criterion, which makes a relay path to avoid DRP resource reservation conflicts and guarantee QoS more stably through cross-layer link adaptation of cooperative relay transmission scheme and is compliant with the current WiMedia D-MAC protocol. Simulation results demonstrate performance improvements of the proposed method for throughput and QoS provisioning.

• Journal of Communications and Networks
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• v.7 no.1
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• pp.45-53
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• 2005

In this paper, we present a cross-layer analysis of wireless TCP systems over correlated channels. The effects of error correlation on the behavior of link retransmission strategy and the end-to-end throughput of TCP layer are investigated. Based on the cross-layer analysis, an efficient refinement of link layer protocol is proposed by consciously utilizing the information of channel correlations, which leads to the performance improvement of wireless TCP systems.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.337-341
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• 1991

Fieldbus is a low level serial digital network which will be used for factory automation. This paper describes lower layer implementation of a Fieldbus network interface. Physical layer provides hardware interface between IBM-PC and Fieldbus. Also, physical layer uses manchester coding, shielded twisted pair lines and RS-485 electrical standard. Data link layer includes Intel's iDCX96 real time executive for 8797 one chip microcontroller and Fieldbus data link protocol software.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.578-580
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• 2009

Wireless Sensor Networks(WSNs) has been used for various applications. It is optimized to low power operation than various function and transmission reliability because of limited power by batteries. but it is necessary to guarantee of reliability for using exact data for more diversity purpose. In WSNs environment composed by multi-hop, it is guarantee to end-to-end transmission reliability based hop-by-hop reliability. however, IEEE 802.15.4 standard is not consider link-layer reliability. in this paper, we propose energy efficient Reliable Link-layer Protocol for Wireless Sensor Networks.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.90-90
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• 2000

The FAS protocol of FOUNDATION Fieldbus playes the roles of interface between Data Link Layer and application layer and establishment of connection between receiver and sender. In this study, the FAS protocol of FOUNDATION Fieldbus was developed. The method of implementation is described in this paper. Software of FAS protocol was implemented by Window-based program and DOS-based program for PC and sensor module, respectively.

• Journal of Communications and Networks
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• v.17 no.2
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• pp.172-183
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• 2015

To provide an efficient link maintenance approach, we propose a cross layer medium access control (LM-MAC) protocol for multichannel cognitive radio ad hoc networks. Link establishment and reliable transmission are two key problems for a perfect link maintenance mechanism. Since the cognitive user (CU) pairs have to reestablish their links each frame, in the proposed MAC protocol, three different access modes are designed to guarantee transmission efficiency in continuous frames. To enhance the transmission reliability, each CU will create a father spectrum list (FSL) after joining in the network. FSL is divided into three groups of sub-channels with different functions to compensate the packet loss caused by the primary users' appearance and the deep fading. Meanwhile, since the transmitter and the receiver will share the same FSL, periodical cooperative sensing is adopted to further optimize the former problem. Finally, compared with the existing opportunistic multichannel (OMC)-MAC protocol, the proposed LM-MAC protocol achieves better system performance in terms of saturation throughput, continuity and access delay.